Four newborn wood mouse babies

Helpless young

Helpless, or altricial, young describes babies that are not very well developed and are utterly incapable of taking care of themselves. Humans, rats and blue tits are prime examples. The young are often hair, or furless, can't yet walk or fly, and are often blind. They rely entirely on their parents for warmth, transport and food. Usually, altricial babies are a feature of big litters, though humans are an obvious exception here. The opposite of altricial is precocial . active, mobile offspring.

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Animals with this behaviour

Mammals

Birds

Reptiles

Amphibians

Cartilaginous fish

Ray-finned fishes

Insects

Arachnids

Crabs, shrimp and krill

Snails and slugs

Clitellata